


Fire and Fury

by LedgendWeaver



Category: Underfell - Fandom, Undertale (Video Game)
Genre: Abuse, Alternate Universe - Underfell, Depression, Frisk is 12, Frisk is a girl, Gaster Blasters, Night Terrors, Nightmares, Papyrus is a dick, Possession, Sans dosnt have his powers, Underfell AU, Underfell Papyrus, Underfell Sans
Language: English
Status: In-Progress
Published: 2016-02-26
Updated: 2016-03-27
Packaged: 2018-05-23 09:45:39
Rating: Teen And Up Audiences
Warnings: Major Character Death
Chapters: 4
Words: 4,371
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/6112642
Author URL: https://archiveofourown.org/users/LedgendWeaver/pseuds/LedgendWeaver
Summary: <blockquote class="userstuff">
              <p>Frisk falls into the Underground, and finds herself in a struggle against powerful creatures, fighting to befriend them, and convince them that not all humans are evil.<br/>She soon realizes that there is another greater issue, the massacre of a civil war and the conflicts that still remain strong. And, with the murder of the adults and children who have fallen before, she knows that most monsters will have no future on the surface.<br/>Amid her struggles, she somehow befriends the single monster who has not killed in perhaps the entire Underground. And while he is even weaker than she is, perhaps, together, they can reach the surface.<br/>Before they are consumed by the Fury of the Underground.</p>
            </blockquote>





	1. Loss

**Author's Note:**

> Well, here goes nothing!

The Cores golden light streamed through the windows, illuminating the hallway. Somewhere in the distance, a bell toled, the sound breaking the silence of the hall.  
Slowly the sound faded away, and was replaced by the sound of footsteps.  
A small shape was skipping their way down the hallway. Her tangled, messy, dirty hair hung in her face, dirt and dust covered her from head to toe, and a wide grin was plastered to her face. The lighting lit up her left side in bright, happy colors, while casting the other half in darkness.  
She hummed a happy tune, twirling a sharp knife in her hand. She blinked, and the smile faded as she came to a stop. He felt a twisted parody of satisfaction at the look of confusion on the brats face.  
The confusion faded as the child recognized the figure standing before her, and for a second, regret flickered across their face, before being quickly replaced as the child lifted her blade gleefully. Tears trickled down the kids cheeks, leaving clean trails in the grime and dust, the only sign of inner conflict as a twisted grin spread across the brats face.  
Something deep inside him, that was part of him, but at the same time, wasn't, growled at the sight of the childs smile.  
But, as he looked at the child again, and, for a second, saw absolute devastation and grief in the momentairly green eyes that looked back at him, Sans was surprised at the feeling of regret he felt. Why was he sorry? Who was this kid, and why did he care about them? He felt a tug on his neck as something flapped in the slight breeze that flowed through the hall. He looked down in surprise and reckonigtion. Why was he wearing Papyrus' cape as a scarf? And whose clothes were these? For some reason, Sans was wearing a blue, fuzzy hoodie; a white, comfy T-shirt; a pair of black shorts with white stripes going down the sides; and a pair of pink, fluffy slippers. What the hell was going on?  
He reached up unconciously to touch the scarf/cloak, its rough fabric reassuringly familiar.  
A memory surged forth; his vision blurry with tears, he was sitting in the snow, in the foggy area outside of Snowdin and Waterfall. He watched as the kid kicked and danced in a pile of dust, spreading it out in the snow so that it would be impossible to tell them apart. The only thing she left for him to mourn over, was a bright, energetic, lively orange scarf/cape, that was now stained grey by the dust of its former owner.  
"Heya. You've been busy, huh?" Sans heard himself say. What was he doing? The kid had probably killed who knows how many monsters to get here, wherever "here" was. It had killed Papyrus. Why wasn't he killing the brat already?  
"Let me ask you a question. Do you think even the worse person can change? That everyone can be a good person if they try?"  
What was this garbage?! Was he really trying to reason with the brat?!  
Naturally, the kid looked at him incruendensly before bursting with laughter. She held her sides as the laughter faded into an insane fit of giggles. Finally, she wiped the tears from her eyes, grin returned, and took a step forward, knife at the ready.  
He could feel more words coming, but he didn't want to wait any longer. A voice deep within him was screaming at him to attack, to kill the brat, and Sans eagerly obeyed.  
He lifted his hand, calling his magic. He was surprised how easily it came, and how much of it there was. He had never felt so strong before. The kids soul turned blue (blue?) and with a flick of his hand, he sent them flying into a pillar with a loud 'crack!'. He laughed and sent them smashing into another pillar, and back again.  
He felt his turn come to an end, and he eagerly waited for the kid to make their move. He shifted as the kids knife swung at him, surprised at how easy it was. "What, did you really think I was just gonna stand there and take it?"  
In the back of his skull, he could feel a building pressure as something, something's, clamored for attention, eager to be released.  
Curious, he called forth one, and gave a jump of surprise when a giant floating skull, with the tiniest hint of a shadowy neck that faded into nonexistence. Sans nearly staggered as he felt his connection to it sharpen, and a wave of raw emotion rolled over him. Somehow, he managed to stay calm among the mealatorm, and focused on the child. A surge of anger came from the skull as it focused on the child, and it's lower jaw split in half. It let out a sharp whine as energy built in its jaws. With a shriek, a beam of pure energy surged from its maw, oblitering the child to dust.  
He felt a surge of exhilaration rush through him, and he tried to do it again. The creature hummed with power, but then, abruptly, it's mouth snapped shut and it began to glitch. Sans tried to reach for it, and it's brothers, but his grip slipped, as something tore it from him.  
He looked down as the light blue sliver that was his soul manifestated. Everything faded to black as he struggled to keep himself together.  
He could feel the connection he had with the creatures snap one by one, and parts of his soul turned grey and crumbled to dust. He staggered as he felt the last connection go taut.  
The force pulled, determined to break the connection. Sans could feel it tgreatening to snap, and a web of cracks began to apear in his soul. The creature was not like the others, it was interwoven with his being, and it was tearing itself and Sans appart in its frantic fight to hold on. He felt the force pull harder, and the connection snapped. Sans soul began to crumble, and the Creature roared in rage. The force pulled again, dragging it towards the darkness, which opened up to swallow it.  
*But it refused.  
He felt the creature grab at him, refusing to let go. It's touch burned, but not in a bad way. He felt every fiber in his being come alive as the creatures held him close. Sans eyes widened when a soul, the creatures soul, a deep cobalt blue sliver of a soul, manifested in its chest. He could feel it reach out for his soul.  
It looked like a perfect fit, and he started to reach back with his soul.  
...  
..  
.  
He hesitated.  
...  
And, the creature, the dream, and his chance, were all torn from him.  
.....  
....

Sans shot awake with a scream of pain, as his half-soul wrenched with agony. He clawed at his rib cage, trying to reach the DETERMINATION covered lump, desperate to rid himself of the pain. The red goo coated the once-blue shard; a large clot of it was stuck to its side like a tick, pulsing with every wave of pain, the source of the dark red veins that ran beneath the surface of the other, lighter DETERMINATION, and penetrated into his soul like roots  
The goo stuck to his bone fingers as he clawed at it, and it burned. He stiffled a scream, and jerked away, and tried futile to scrape it off. He finally stopped struggling, and lay there in bed, panting in exhaustion as he waited for the pain to pass.  
Slowly, the red substance leaked into his fingers, and he shuddered in pain. He froze, barely breathing as he strained to listen into the room on the other side of the wall.  
He heard the ruffle of bedsheets, and some dark mutterings, but no sign that Papyrus was going to burst into his room tonight. He sighed in relief, even though he knew full well that he probably would be punished in the morning.  
As the pain subsided, except for his soul's continuous, dull throb of pain, which was nothing new, he was filled with a sense of loss.  
The sigh of relief was chocked out by the lump forming in the back of his throat. Blue tears laced with red prickled at the corner of his sockets. His attempts at taking calming breaths turned into sobs. His soul throbbed with each sob. He felt so...empty inside.  
He pulled his covers close, balling them up, and hugging them close, pressing his face into them as he tried to smother the noises, terrified of Papyrus' reaction.  
Finally, the cries faded into soundless tears, and, exhausted, he drifted off into an empty, dreamless sleep.  
...

Papyrus had been sleeping dreamlessly, when, abruptly, he felt Dage surge. He had shot awake, and found himself in a mental battle as he fought to keep the creature contained. It had gotten dangerously close this time.  
He slowly lay back down, grinning, exhaustedly, in victory as the creatures struggles against its bindings stilled. He closed his eyes, and drank in the raw power of its anger.  
He could hear soft sobbs through the wall, and he sneered in disgust, and he briefly considered getting up to punish his brother for his weakness. But, that wouldn't be wise. Dage might be settled down now, but it was best not to rile him up so soon.  
Papyrus rolled over on his side, he would punish him in the morning. He was certain his brother would do something punishable, and then...  
He smiled as he felt Dage stir protectively. After the accident that left Sans with half a soul, Papyrus' father had told him of the demonic creatures that were slowly consuming him. Gaster had warned him that Sans would be more vulnerable than ever, and Papyrus had to keep a close eye on him, to ensure he never became bonded. Papyrus had, and had interfered when Dage had pulled Sans mind and soul into the Nothingness.  
Papyrus grimaces at the thought of Sans of all monsters, using Dage. He was too weak, he didn't deserve the raw power that was the creature.  
He waited for the sounds on the other side of the wall to fade into silence, before he rolled onto his side, and went back to sleep.


	2. Below

**Summary for the Chapter:**

> Frisk arrives in the Underground.

**Notes for the Chapter:**

> Frisk is a girl in this, sorry if that bothers you. She is around fifteen, and I'm not sure what the situation on the surface is. I just now that if she does have a family, then she has a very loose connection to them, and that she is fairly used to survival on her own (mostly).  
> Huh, I wonder if there is any difference in the size of this chapter from the last one.  
> hmmmm...

Frisk slowly became aware of her surroundings. Laying on her back she stared up at the tunnel she had fallen into. Her body was sore, but miraculously, nothing was broken.  
She sat up slowly, and toon in her surroundings. She was laying in a bed of dead plants, that crunched slightly as she moved, and she was surrounded be smooth, stone walls. She stood shakily, and did her best to brush dirt and crushed stems and leaves off her pants. The dead plants crunched under her shoes as she made her way through the brush.  
Finally, she stepped onto cool, hard stone, and looked up to face the dark tunnel that led deeper into the caverns.  
On the surface, the sun was rising, and was at the perfect aangle for its light to enter the cave the hole she had fallen into was in. A faint breeze stirred her hair as she stared into the impenetrable darkness.  
*The warm touch of the sun on your back, the cool breeze wafting from the pitch black tunnel, and the promise of the unknown, fills you with DETERMINATION!

**Notes for the Chapter:**

> Sorry that the chapters are taking so long. I decided to divide this one, so I could get something out. I am so happy that so many people have read this already! Thank you for supporting me! :)


	3. Found

**Summary for the Chapter:**

> Frisk encounters her first monster

**Notes for the Chapter:**

> Some conflict involving water, so if you are sensitive to that kind of stuff, then read with care. I wasn't as detailed as I could have been, thankfully, so it shouldn't be too bad

Frisk let a hand drift out to brush against the wall as she felt her way through the darkness. The stone was slick with moisture and cold to the touch. The smooth, round tunnel had been carved out by an ancient subterranean river, whose only remains was a trickle snaking its way down the cavern.  
Frisk became aware of a soft sound. It echoed hauntingly, and she shivered. She came around a bend, and halted, her eyes widening in amazement. The river tunnel came to an end, opening up into a massive cavern, that had once been an underground lake. A hole on the ceiling, similar to the one she had fallen in, had been blocked up. The trickle running between her feet slipped over the ledge, feeding a glowing, blue pond. The pond reached the center of the cavern, where a meadow of dimly glowing, white flowers grew around its banks and upon a small lump of earth.  
She took a step forward, and gave a yelp as the stone under her foot crumbled. Her arms waved franticly in the air as she fought to stay balanced on her one foot. She toppled forward and she screamed as she tumbled down towards the pond.  
"Splash"  
.  
Frisks back hit the water with a painful slap, and the ar was forced out of her in a cloud of bubbles.  
Frisk righted herself, and kicked frantically towards the surface, but she continued to sink deeper. Her soaken sweater weighed a ton, and her stiff snow boots prevented her kicks in making any real difference. A current was tugging at her, and the surface was steadily drawing away.   
Her lubgs were screaming for air as she floundered, fighting against the weight of her sodden clothes. She kicked off her shoes and slipped her arms out of the thick, wool sweater she had been wearing over her white undershirt.  
Freed from its weight, she kicked harder, her legs becoming tired from the strain, her arms pulling and dragging at the water frantically. Her vision began to grow dark.  
.  
..  
...  
....

With a gasp, her head broke the surface of the deceptively deep pond. She lay flat on her back, allowing her natural buoyancy to keep her afloat, her arms gently stirring the water beneath her as she panted heavily.  
Slowly, the echoes of her gasping faded away, and she swam towards the closest bank.  
She crawled out of the water fighting frantically to keep herself from slipping on the ssmooth, wet, stone. Her fingernails scraped pai fully on stone as she slipped back into the deep water. She swam towards a different bank, the one with that the flowers grew near and on.  
This time, as she began to slide back ibto the water, she grabbed the closest flower, and was surprised when it held.  
She managed to pull herself up, and crawled a bit further. Water poured off of her in torrents, and her pants made wet, slapping noises whenever they touched the ground.  
She lay down on her back slowly, still panting, and just layed there for a few moments, staring up at the glowing crystals overhead. A soft breeze cut through her wet clothes and skin, and she shivered violently. A faint whispering sound came from the flowers around her, and she found it oddly comforting. She felt her eyes began to drift close...

"Wh-whose th-there?" whispered a soft voice. Frisk nearly shut eyes snapped opened as she shot up, scanning the meadow for the source.  
She stood up, swaying slightly, and stepped made her way through the calf-high flowers. She approached the lump, and, for the first time, she noticed the small gravestone. Her eye was caught by the two flowers that grew by and on the otherwise bare grave.  
At the very center of the grave, a large, flower was growing. It's stem was coal black, as were its diamond shaped leaves. It's petals were colored like fire, their bases were red, which became streaked with orange towards the middle, and the tips were starburst of a bright yellow. It glowed brightly in the gloom, giving off the same comforting glow of a campfire.  
The second flower was growing at the foot of the grave. It's stem and leaves were also black, but it's shape was the same as the ones around her. It was colored like a tiger lily, but instead of orange and black, it was white and black. And unlike any of the flowers Frisk had seen down here so far, it didn't glow.  
The flower swung around to face her, and she blinked in surprise at the small face on the disk of the flower. It snarled at her, but any intimitadion it might have had was undermined by the small glowing pinpricks of water at the corner of its eyes. The soft sound she had heard earlier must have been it crying.  
The flowers eyes wwidened, and she saw a flicker of... recognition? "Y-you", he whispered in a trembling voice. Thenthe flower shook itself, and glared at Frisk again. "Who are you?! What do you want?!" he demanded.  
Frisk gently kneeled on the ground, smiling gently at the flower. The flower snarled, and white, oval orbs appeared over its head. Red mist gathered on her skin, and a soft, red glow emerged from the center of her chest. She looked down to see the source was a heart shaped object lingering just under her skin.  
Looking back up at tge pellets, she swallowed uneasily, but resisted the urge to run. "I-I'm not going to hurt you," she said gently, her hands held open, palms facing the flower in a display of peace. "My name is Frisk, what's yours?"  
Slowly, the white things disappeared, and Frisk let out an inward sigh of relief. The flower glarrsd at her suspiciously, and finally said, "Flowey, Flowey the flower."


	4. Knock-knock

**Summary for the Chapter:**

> A little background on Toriel and the Fury. And the reappearance of my favorite character.

**Notes for the Chapter:**

> Sorry this took so long. The hardest part was coming up with a decent knock-knock joke that made sense in the situation. I ended up splitting the chapter in half, but we should be getting back to the story soon.

When the Fury had first appeared in the Ruins, Toriel had been the first infected, as the trail of black goo came directly under her door, through her house and out to the Ruins beyond. The she had been fervently scrubbing it off, flecks of it had splattered on her fur.  
The Fury had affected the smaller, less intelligent monsters of the Ruins the worst, turning them practically rabid. Toriel was forced to kill when she was cornered by a group of them. Already unstable since the incident that had led her to fleeing the castle and shame and the burying of her two children, the pain and confusion brought by the Fury drove her over the edge.  
When the humans began to fall down, she killed the younger ones and hid from the older ones, locking the door of her house so they could not leave the Ruins, and most eventually starved. While others did get out, She was fairly certain nothing but bodies reached Asgore.  
She would slip a poison and a sleeping potion into her pies, would feed the children, who would crawl into bed, and died a painless death. The children were almost always infected with the Fury by then, and were screaming and spasming in pain.   
The first time a child had fallen after the Fury had appeared, Toriel had still been struggling against it, and had given the infected child a sleeping potion, and had awoken to the child trying to stab her with a kitchen blade.  
Toriel did not know the nature of the disease or humans, and how it affected them. When the black goo infected a human, it infested their DETERMINATION, and waited. When that human inevitably died and LOADED, it would infect the rest of their body, mind, and even soul. Making it a puppet of the parasite. If the human did not for, the parasite would eventually consume their soul and DETERMINATION, and the lifeless husks would crumble to dust.  
Driven insane by the Fury, her LOVE, and her guilt, Toriel withdrew into her house, shutting the door, and ceased to water the white flowers that had grown over her children's graves.  
Over 51 humans had fallen into the Underground, 7 of whichs souls and DETERMINATUON had been absorbed by the parasite, by the time that the hole had been covered. Toriel did not know this, only noticed that humans had stopped coming.  
One day, she had been sitting in her chair, staring at a book, not reading, just staring, when she had heard a muffled, distant knocking sound. No one was at the front door, so she checked the basement.  
...

Toriel huffed, as she searched the basement for a monster. Most likely, it was a Froggit that had become traped in a box.  
Free EXP  
She heard the knocking sound again, and realized that it was not coming from any of the stuff stored in the basement, but the door itself. She carefully approached it, and leaned forward, head tilted to listen.  
For a second, everything was quiet, when the knock came again. She heard a voice mutter something on the other side.  
With sadistic glee, Toriel reached for the door. Whoever this monster was would probably be worth much more EXP than a Froggit.  
As the door began to open with the grinding of stone, she heard a yelp, and felt the pressure in the air drop momentarily. Toriel looked around, and frowned. The monster had disappeared.  
Toriel shut the door, pulled up a box, sat down, and waited. She might have dozed off for a bit, because at some point, she woke up to a sore body. But her patience was rewarded with another knock.  
She reached to open the door again, but paused. Their was a rhythm, a repetition to the knocks that was oddly familiar.   
Her curiosity peaked, she pressed her ear to the door. The knocks were much softer this time, but she was able to make out his (his voice was masculine) words.  
"Dishes"  
.  
..  
...  
"Dishes a bad joke".  
She couldn't help the snort that escaped her from the absolute ridiculousness of it all. He was telling knock-knock jokes. She heard the sound of retreating footsteps, and she realized that he had naturally heard her snort and run off.  
She was surprised by the disappointment she felt at this. Somehow, just two words had reminded her if a much...happier time.  
...

Every day, Toriel would sit on the box, and wait for the boy to come back. And he always did. She had learned her lesson, and didn't make any noises.  
She tried to convince herself that she was just biding her time, but she knew, deep inside, it was more than that. She could hear his raw loneliness and fear in his voice. She had not heard, or experienced those emotions in a long time.  
She was also surprised that he hadn't run out of jokes yet. She planned on waiting until she had heard them all, and then she would kill him.  
So, she began bringing a journal down to keep record, and wrote down all the ones she could remember.  
...  
One day, when he came, he sounded different. Whenever he spoke, she heard a clicking noise as if their was something wrong with his jaw. He was much more somber, not even chuckling at his own jokes like he usually did.   
"Why didn't the skeleton go to the dance?  
.  
..  
...  
"Because he had no body to go with  
"You've already said that one," she thought out loud.  
She froze, and waited to her the sounds of retreating footsteps, but heard only silence. She was about to leave, when she heard a hesitant knock.  
"Knock-knock".  
She froze. "What are you doing? I could tear you to pieces! Go away!!"  
she hissed. She pulsed her magic, and the air simmered with heat, crackling with energy, as she let her aura blossom forth, showing how powerful she was.  
"Knock-knock", more insistently this time.  
Toriels mind spun as she tried to find logic in his actions. As far as she could tell, he wasn't stupid, or at least he was smarter than a Froggit, and even those things wouldn't seek out confrontation with a stronger monster on their own. He could be insane, but she doubted it. So, why wasn't he running away in fear, unless-  
A chill of fear went down her spine. Unless he knew he had nothing to fear from her.  
She leaned away from the door, her mind racing. Yes, it all made sense know. Why he was able to tell jokes with nearly complete lack of fear, why he wasn't crying in fear at the presence of such a powerful for separated from him only by a door.  
Because he had nothing to fear from her.  
Yes, it was only logical. She had noted before he was weak in magic, but she had not taken in account his physical strength. Whoever he was, must be extremely powerful.  
"Knock-knock",he said again.  
Was he toying with her? Yes, he must be. A spark of hope filled her. Maybe...maybe if she pretended to be interested, maybe if she laughed at his jokes, maybe he would be appeased, maybe he wouldn't kill her immediately.  
"W-who's t-there?" she answered in a trembling voice.  
"Ben"  
"Ben, who?"  
"Ben knocking on this door for the last ten minutes. How long have you been there?"  
"...The entire time, and the day before that, and the day before that, and..." She let her voice trail off into silence.  
She heard the shuffle of cloth as someone leaned against the door and sat down. She stiffened slightly at the knowledge that only an inch of stone was keeping him apart from her. She began to tremble slightly.  
"...Knock, knock"  
This again? Why didn't he just get it over with, or leave?  
"Who's there?"  
And so, he told her another knock-knock joke, and another, and another. Eventually, he left, but he returned the next day. And the next, and the next.  
She didn't understand why, why was he doing this. Didn't he have anything better to do?

"Okay, I got another one."  
She sighed," Fine, go ahead."  
"You have to start it."  
"Fine, Knock-knock."  
"Who's there?"  
She opened her mouth, and closed it, realization hitting her. She heard a dark chuckle through the door. She searched her brain for any knock-knock jokes that she knew, for some reason, that he hadn't already said.  
"O-old Lady"  
"Old lady, who?"  
"Oh, I did not know you could yodel".  
...

He burst out laughing. "Okay, that was a good one".  
She couldn't help but smile a bit.   
She heard him move, as he got up again, and she was surprised by the prickle of disappointment she felt at him leaving.  
...

**Notes for the Chapter:**

> I can't wait until later, I got some really good twists and turns planned. This is going to be great!

**Author's Note:**

> I don't really have a writing schedule for this Thing, so the posting might take a while. Sorry!  
> Don't be afraid of leaving comments and feedback!


End file.
